/**
 * Copyright 2010-2013 Ralph Schaer <ralphschaer@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package ch.ralscha.extdirectspring.filter;

import java.util.HashSet;
import java.util.NoSuchElementException;
import java.util.Set;

public enum Comparison {
	LESS_THAN("lt", "<"), LESS_THAN_OR_EQUAL("lte", "<="), GREATER_THAN("gt", ">"), GREATER_THAN_OR_EQUAL("gte", ">="), EQUAL(
			"eq", "="), NOT_EQUAL("ne", "!="), LIKE("like"), IN("in");

	private final Set<String> externalValues;

	private Comparison(String... values) {
		externalValues = new HashSet<String>();
		for (String value : values) {
			externalValues.add(value);
		}
	}

	public boolean is(String externalValue) {
		return externalValues.contains(externalValue);
	}

	public static Comparison fromString(String externalValue) {
		if (externalValue != null) {
			final String externalValueLowerCase = externalValue.toLowerCase();
			for (Comparison comparison : Comparison.values()) {
				if (comparison.is(externalValueLowerCase)) {
					return comparison;
				}
			}
		}
		throw new NoSuchElementException("Comparison value: '" + externalValue + "' not supported");
	}

}